The present invention is a releasable one way clutch type tension retaining device for use in surgical procedures, such as arthroscopy, for example, wherein an instrument which has a shaft portion and a working end is inserted through a body surface to engage and stretch under tension material, such as cartiledge, muscle or fatty tissue, for example, either to hold the material to be worked on by another instrument or to hold the material away from underlying material that is to be worked on. The instrument applies tension to the material by being drawn outward from the body.
The device of this invention is adapted for use with a number of different surgical instruments in a variety of surgical procedures. For example, it is particularly adapted for use with different types of grasping forceps for retaining tension during knife cutting or shaving procedures. It is also used with fat pad retractors for holding pads of fat out of the way for cutting, shaving or suturing in areas under the fat pad. It has also been used to hold a retrograde marking hook in position during arthroscopic reconstruction.
The device includes a tubular section through the bore of which the shaft of a surgical instrument is received. The tubular section is slideably received within the bore of a sleeve element and a one way type of clutch mechanism is provided by at least one roller through and movable up and down in a notch that is in the wall of the tubular section. The notch is across the axis of the tubular section and opens into its bore. The notch is of a depth such that the space between the the roller resting in the bottom of the notch and an opposite surface, which may be the opposite wall of the bore of the tumular section or, preferably, another roller in another notch through the opposite side of the tubular section, is less than the diameter of the shaft of an instrument that is to be used with the device.
The ends of the roller, or rollers, are rotatably received respectively in slots in opposite walls portions of the bore of the sleeve element. The slots extend generally longitudinally of the bore of the sleeve element, but at an angle with respect to the axis of the bore so that the plane of the slots converges toward the opposite wall of the sleeve element bore in one direction and diverge from it in the opposite direction. Thus when the notched tubular section is moved within the sleeve element relatively in the direction in which the plane of the slots converges toward the opposite surface within the sleeve element the notch carries the roller toward that opposite surface, and hence toward the opposite surface within the bore of the tubular section. The latter surface may be the opposite wall of the bore of the tubular section or, in the preferred form, the surface of another roller in another, oppositely disposed notch in the opposite wall of the tubular section, the end portions of this other roller being received in another pair of slots in the walls of the sleeve element. The plane of such a second pair of slots would converge toward the opposite wall of the sleeve element in the same direction as the plane of the first pair of slots and at the same longitudinal location relative to the length of the sleeve element.
In any case the relative movement of the tubular section within the sleeve element in the slot converging direction causes the roller or rollers to pinch an instrument shaft that is through the bore of the tubular section between it and the opposite surface, which is either the bore wall or another roller.
Spring means is connected to urge the parts in relative directions in which the roller, or rollers, are urged into instrument shaft gripping position. Thus an instrument whose shaft is through the bore of the tubular section is prevented from being drawn further through the tubular section in the converging direction of the slots by the pinching action of the roller or rollers , but may be drawn in the opposite direction, the direction in which the slots diverge.
The spring means is releasable to enable an instrument shaft to be moved freely through the bore of the tubular section in either direction when desired. In a preferred form of the device of this invention the spring means is a spring loaded lever pivotted on the sleeve element and having an arm connected to an end of the roller, or to one of the rollers, if there are two, to urge the roller in the converging direction.
A broad circular pad is mounted on the end of the sleeve element toward which the plane, or planes, of the slots therein converge toward the opposite side of its bore. This pad is removable and replaceable for hygenic purposes and is adapted to bear against the surface of the body against which the device is placed in use in order to distribute the load exerted by the device on the body surface and thus cushion the device.
With the device placed with its pad against a body surface the shaft of a surgical instrument, such as grasping forceps, is through the tubular section and the working end of the instrument, e.g. the jaws of grasping forceps, projects through the body surface to the inside of the body where it is applied to grip or hook onto material--tissue, muscle or cartiledge, for example--within the body. The instrument is then drawn outward through the device is stretch or pull the material outward to the desired degree of tension. The slots, notch and roller clutch mechanism then operates to hold the instrument and the material held by it in the desired position by means of the tension created by the stretched material pulling inward on the instrument. The device then maintains the instrument in the tension position and frees the hands of the doctor or nurse for other work. When the work is completed the tension is relieved to allow the instrument to be move inward to detach it from the material in the body and then withdraw if from the body, by actuating the spring means to release the grip of the roller, or rollers, on the instrument shaft.